RNA Viruses PDF

RNA VIRUSES Single-Stranded Double-Stranded Positive-Stranded Negative-Stranded Naked Enveloped Enveloped Naked *PICORNA *TOGA BUNYA...

RNA VIRUSES Single-Stranded Double-Stranded Positive-Stranded Negative-Stranded Naked Enveloped Enveloped Naked *PICORNA *TOGA BUNYA ORTHOMYXO *REO *CALICI *FLAVI PARAMYXO CORONA RHABDO (bullet-shaped) ARENA *Icosahedral; the rest have RETRO FILO helical symmetry POSITIVE-SENSE RNA VIRUS PICORNAVIRIDAE ENTEROVIRUSES B. POLIOVIRUS 1. ADENOVIRUS Transmission: 2. COXSACKIE A VIRUS Ingestion of food and water contaminated with poliovirus 3. COXSACKIE B VIRUS 4. ECHOVIRUS Presentations: 5. HEPATITIS A VIRUS 1. MILD FEBRILE ILLNESS → most common presentation; self-limiting 2. PARALYTIC POLIOMYELITIS A. RHINOVIRUS → virus destroys the presynaptic motor neurons in the anterior → More than 100 serotypes horn of the spinal cord (central motor neuron deficits) as well as → Most common cause of cough and colds the postsynaptic neurons leaving the horn (peripheral motor neuron deficits) Transmission: → flaccid paralysis (a leg or arm, paraplegia, quadriplegia) Hand-to-hand spread of mucous membrane secretions → painful muscle spasms (asymmetric muscle paralysis that results to atrophy and loss of reflexes) POSITIVE-SENSE RNA VIRUS PICORNAVIRIDAE POLIO VACCINES SALK SABIN (Jonas Salk) (Albert Sabin) Aka IPV Aka OPV Contains attenuated poliovirus Contains formalin-killed virus Intramuscular administration Oral administration POSITIVE-SENSE RNA VIRUS PICORNAVIRIDAE C. COXSACKIE A VIRUS D. COXSACKIE B VIRUS Presentation: 1. HAND-FOOT-MOUTH DISEASE Presentations: → HERPANGINA: vesicles/ ulcers in the pharynx 1. PLEURODYNIA → inflammation of the covering of the lungs → fever, HA, sever lower thoracic pain on breathing 2. MYOCARDITIS – PERICARDITIS → infection and inflammation of the heart muscle and pericardial membrane that can result in self-limited chest pain or more serious arrhythmias, cardiomyopathy, and heart failure Hand-Foot-Mouth Disease POSITIVE-SENSE RNA VIRUS PICORNAVIRIDAE E. HEPATITIS A VIRUS/ ENTEROVIRUS-72 Transmission: Fecal-oral route (associated with street foods) SEROLOGY IgM anti-HAV IgG anti-HAV Presentation: 1. HAV INFECTION/ INFECTIOUS HEPATITIS Acute infection + - → Mild condition where most patients recover fully Old infection - + Prevention: HAV Vaccine Incubation or no infection - - POSITIVE-SENSE RNA VIRUS CORONAVIRIDAE A. HUMAN CORONAVIRUS B. MERS-CoV C. SARS-CoV2 Transmission: Zoonotic Coronavirus Zoonotic Coronavirus Respiratory Route Transmission: Transmission: Respiratory Route Airborne Presentation: Incubation Period: 14 days 1. COMMON COLDS Presentation: 2. GASTROENTERITIS → Severe respiratory symptoms Presentation: Cough and colds (65-80%) Fever (85%) Cause of Colds C. SARS-CoV1 SOB (20-40%) Zoonotic Coronavirus #1 Rhinovirus HA Transmission: Fatigue #2 Adenovirus Respiratory Route (2003 Loss of sense of smell and taste #3 Coronaviridae outbreak) #4 Orthomyxoviridae #5 Paramyxoviridae Presentation: → Severe respiratory symptoms POSITIVE-SENSE RNA VIRUS TOGAVIRIDAE Arthropod-Borne A. ALPHA VIRUS Presentation: 1. CHIKUNGUNYA → Vector: Aedes aegpti → caused by Chikungunya Virus → sudden onset of high fever and rashes → joint pain (differentiates it from Dengue infection) Chikungunya Rash POSITIVE-SENSE RNA VIRUS TOGAVIRIDAE Non-Arthropod Borne B. RUBIVIRUS Presentation: 1. RUBELLA/ GERMAN MEASLES FEVER (3-day fever) 3rd Disease RASHES: starts on the face – downward progression → appears 2-3 weeks after infection → patient shed virions in respiratory droplets for approximately two weeks before and two weeks after the rash Rubella Rash 3C’s (Cough, Colds, Coryza) → Prodrome Symptoms Posterior lymphadenopathy Forchheimer spots (20%; non-specific to Rubella) → small, red spots in the soft palate POSITIVE-SENSE RNA VIRUS TOGAVIRIDAE Non-Arthropod Borne B. RUBIVIRUS Presentation: 2. CONGENITAL RUBELLA SYNDROME “Bobo” Mental retardation, microcephaly “Bulag” Blind “Bingi” Deaf “Butas ang puso” CHD (patent ductus, interventricular septal defects) “Bugbog” Petechial patches 3C’s - CATARACT - CARDIAC DEFECT - CONGENITAL DEAFNESS POSITIVE-SENSE RNA VIRUS CALICIVIRIDAE A. NORWALK VIRUS Presentation: 1. GASTROENTERITIS B. HEPATITIS E VIRUS Transmission: Fecal-oral route Presentation: 1. ENTERIC HEPATITIS POSITIVE-SENSE RNA VIRUS FLAVIVIRIDAE Arthropod-Borne A. DENGUE VIRUS 4 serotypes Transmission: Mosquito-Borne Female Aedes aegypti Day biter (6-8AM; 4-6PM) Presentations: 1. DENGUE FEVER/ BREAKBONE FEVER 2. DENGUE HEMORRHAGIC FEVER → high fever accompanied with severe HA, pain behind → severe form of dengue fever the eyes, muscle and joint aches, N&V, and a → critical monitoring of patients after 3-5 days post onset of characteristic skin rash dengue fever symptoms → bleeding, thrombocytopenia, and blood plasma leakage → + hypotension ( DENGUE SHOCK SYNDROME) Treatment: Supportive Care Prevention and Control: Dengvaxia® POSITIVE-SENSE RNA VIRUS FLAVIVIRIDAE Arthropod-Borne A. DENGUE VIRUS Source: https://www.healthxchange.sg/children/health-scares-outbreaks/dengue-fever-severe-dengue POSITIVE-SENSE RNA VIRUS FLAVIVIRIDAE Arthropod-Borne B. ZIKA VIRUS C. JBE VIRUS D. WEST NILE FEVER VIRUS Transmission: Mosquito-Borne Transmission: Mosquito-Borne Transmission: Mosquito-Borne Culex sp. Presentation: Presentations: Presentations: 1. FLU-LIKE ILLNESS 1. ZIKA FEVER 1. JAPANESE ENCEPHALITIS 2. ENCEPHALITIS → mild form of dengue → brain inflammation, seizures, confusion, severe HA, vomiting Vertical Transmission: Microcephaly Brain malformations Treatment: Supportive Birth defects Prevention and Control: JBE Vaccine POSITIVE-SENSE RNA VIRUS FLAVIVIRIDAE Non-Arthropod Borne E. HEPATITIS C VIRUS Summary of Hepatitis Virus and corresponding family Transmission: Same with Hepatitis B Virus Family Presentations: HAV 1. Acute and Chronic Hepatitis HBV HCV HDV HEV POSITIVE-SENSE RNA VIRUS RETROVIRIDAE A. HUMAN IMMUNODEFICIENCY VIRUS Transmission: HIV 1: Pandemic HIV 2: Endemic in West Africa Epidemiology: Source: https://www.h-h-c.com/aids-and-hiv-facts-and-myths-about-transmission/ POSITIVE-SENSE RNA VIRUS RETROVIRIDAE A. HUMAN IMMUNODEFICIENCY VIRUS Virulence Factors: gp41: FUSION PROTEIN gp120: ATTACHMENT PROTEIN REVERSE TRANSCRIPTASE: Converts RNA to DNA INTEGRASE: Incorporates viral DNA to host DNA PROTEASE: Cleaves newly synthesized HIV proteins to activate them POSITIVE-SENSE RNA VIRUS RETROVIRIDAE A. HUMAN IMMUNODEFICIENCY VIRUS Presentation: ACUTE HIV SYNDROME → flu-like symptoms; self-limiting LATENT HIV → asymptomatic but CD4 count is slowly declining AIDS → final stage of HIV infection (very low CD4 count) → Opportunistic infections and AIDS-defining illnesses CD4 count VS Viral Load Source: https://www.hiv.uw.edu/pdf/basic-primary-care/staging-initial-evaluation-monitoring/core-concept/all Treatment: Antiretroviral Drugs  RNA VIRUSES Single-Stranded Double-Stranded Positive-Stranded Negative-Stranded Naked Enveloped Enveloped Naked *PICORNA *TOGA BUNYA ORTHOMYXO *REO *CALICI *FLAVI PARAMYXO CORONA RHABDO (bullet-shaped) ARENA *Icosahedral; the rest have RETRO FILO helical symmetry NEGATIVE-SENSE RNA VIRUS PARAMYXOVIRIDAE A. PARAINFLUENZA VIRUS PRESENTATIONS: 1. URTI infection in adults 2. Common Colds, Rhinitis, Pharyngitis, Sinus congestion 3. Flu-like illness 4. CROUP → Parainfluenza infection of the larynx and URT structures → Barking cough usually at night B. RESPIRATORY SYNCITIAL VIRUS (RSV) Presentation: 1. RSV INFECTION → common colds → most common cause of viral pneumonia in children less than 6 months old NEGATIVE-SENSE RNA VIRUS PARAMYXOVIRIDAE RASH → red, flat to slightly bumpy (maculopapular) → spreads from head to toe C. RUBEOLA VIRUS English Measles - Rash → Can cause abortion and premature delivery Presentations: 1. ENGLISH MEASLES/ HARD MEASLES/ 1st DISEASE Transmission: Inhalation of respiratory secretions. Direct contact KOPLIK’S SPOTS - Pathognomonic INCUBATION PERIOD → small, red-based lesions with blue-white centers at the buccal → 2-week period before rash appearance mucosa usually opposite the molar appears a day or before the PRODROME rash → conjunctivitis, swelling of the eyelids, photophobia, high fever, rhinitis, malaise. Prevention: MMR Koplik’s Spots NEGATIVE-SENSE RNA VIRUS PARAMYXOVIRIDAE D. MUMPS VIRUS Presentations: Presentations: 1. MUMPS/ INFECTIOUS PAROTITIS 2. SUBCLEROSING PAN ENCEPHALITIS → enlarged jaw tissues arising from swollen salivary glands → slow form of encephalitis → whole brain is inflamed → can occur years after initial insult of measles Disease Causative Agent Mumps 1st Disease → about 25% of infected males who have reached puberty can 2nd Disease develop ORCHITIS 3rd Disease → the testes enlarge and stretches the capsule resulting in intense 5th Disease pain; 1% of patient become sterile 6th Disease Treatment: Self limiting Prevention: MMR RNA VIRUS ORTHOMYXOVIRIDAE A. INFLUENZA VIRUS Type B: Humans only - EPIDEMIC Type C: Humans and Pigs - SPORADIC HEMAGLUTTININ (HA) → attachment to host sialic receptors of RBCs and URT cell MUTATIONS of INFLUENZA membranes – VIRAL PENETRATION 1. Antigenic Drift → HA binding to sialic receptors activates fusion of the host → minor antigenic changes; mutations occurring cell membrane with the virion membrane → Adsorption during viral replication *antibodies against HA will block this binding and → causes mild infection prevent infection → 16 types 2. Antigenic Shift → major antigenic changes; complete changes in HA NEURAMINIDASE (NA) and NA (new HA and NA) Neuraminic acid → causes severe to fatal infections → is an important compound of mucin, the substance covering mucosal epithelial cells (sialic acid) → 9 types RNA VIRUS ORTHOMYXOVIRIDAE BUNYAVIRIDAE A. INFLUENZA VIRUS Arthropod-Borne Presentation: 1. INFLUENZA/ FLU A. CALIFORNIAN ENCEPHALITIS VIRUS Common Signs and Symptoms of INFLUENZA B. RIFT VALEY FEVER VIRUS High fever Mosquito-borne Muscle aches Chills and sweats C. SANDFLY FEVER VIRUS HA Fatigue and weakness Sandfly-borne Nasal congestion Sore throat Treatment: Supportive Prevention: Flu Vaccine RNA VIRUS RHABDOVIRIDAE A. RABIES VIRUS →rod/ bullet-shaped virus Reservoir: Warm-blooded animals with salivary glands Presentation: 1. RABIES 1. Acute Encephalitis INUCUBATION PERIOD → hyperactivity and agitation (confusion and seizures) → weeks to years (can be dormant even for 14 years) 2. Classic Brainstem Encephalitis PRODROME → cranial nerve dysfunction → fever, HA, sore throat, fatigue, nausea, and painfully → painful contraction of pharyngeal muscles with swallowing sensitive nerves around the healed wound site. liquids (hydrophobia) – inability to swallow own saliva. 3. Death → respiratory center depression → 100% mortality RNA VIRUS RHABDOVIRIDAE NEGRI BODIES PEP (Post-Exposure → Brain cells demonstrate neuropathic changes and Category Description Prophylaxis) pathognomonic collections of virions in the cytoplasm. Touching/ feeding animals I No PEP Lick on intact skin Nibbling or minor II scratches without Rabies Vaccine bleeding Bites or scratches with bleeding Negri Bodies III Rabies Vaccine + Ig Licks on broken skin NEGATIVE-SENSE RNA VIRUS FILOVIRIDAE ARENAVIRIDAE A. EBOLA VIRUS A. LASSA VIRUS B. MACHUPO VIRUS Transmission: Direct contact to infected body fluids Presentation: 1. VIRAL HEMORRHAGIC FEVER Reservoir: Primates Presentation: 1. AFRICA HEMORRHAGIC FEVER → high mortality rate → requires maximum containment to prevent its spread NEGATIVE-SENSE RNA VIRUS REOVIRIDAE Respiratory Enteric Orphan Virus A. ROTAVIRUS → dsRNA (only) Presentation: 1. VIRAL GASTROENTERITIS → most common cause of viral gastroenteritis Prevention: Rota Series